1. Field of the Invention
The present invention relates to packaging support trays of the type commonly employed in the retailing of prepackaged cuts of meat, poultry, fresh produce and the like. For the most part, such trays are generally characterized by having a relatively flat uninterrupted interior surface for supporting products packaged therein. Such a flat surface has proven undesirable in the packaging of commodities such as meat which contains quantities of natural juices. Such watery juices as they exude from the packaged meat products accumulate in the tray bottom area surrounding the meat as well as in the tray corners, thereby causing the package to have an unsightly and unpleasant appearance.
2. Description of the Prior Art
In the past, attempts to contain liquids which exude from poultry, meat and the like have included the placement of liquid absorbent sheets between the moisture containing product and the tray surface. In addition to the added costs involved when such absorbent sheets or pads are employed, such materials have a tendency to dehydrate the product with which they are in contact. U.S. Pat. No. 2,974,843 discloses the employment of cylindrically shaped cups in the bottom surface of pulp meat trays to entrap liquids therein. Such cups are defined in the patent as having sharply defined vertical side walls and having a diameter fixed within critical limits. U.S. Pat. No. 3,346,400 discloses plastic receptacles for holding a moisture containing food product. The receptacle or tray bottom has a plurality of individual liquid proof wells, of particular dimension, designed to entrap air and liquid when a product such as fresh meat is placed in the tray to overlie the wells. The individual wells in such trays have a uniformly constant transverse dimension (e.g. 1/8 inch in diameter) within certain fixed limits, to insure liquid entrapment therein.
Forming techniques which have been employed in the past to mold liquid entrapping recesses in a tray bottom include, in the case of molded pulp, providing a plurality of nubbins on the surface of the tray forming screen over which an aqueous slurry of pulp is drawn. In such a forming method the nubbins must be shaped so as to produce a fairly uniform cross-sectional recess in the tray bottom or a recess which is wider at its top portion than at its base, otherwise the pulp tray could not be stripped from the molding screen without damaging the tray. Methods which have been employed to produce such recesses in plastic tray structures include either "hot-punching" after the tray has been formed or providing on the heated die that forms the interior surface of the tray, embossing sections to provide recesses in the tray bottom. Again, as in the case of the pulp forming method, the recessed areas so formed must necessarily have either a generally uniform cross section or a cross section which is widest at the top in order to insure ease of removal of the tray from the heated forming members without damage. Such forming techniques necessarily limit the dimensions, and hence the volume of the liquid which may be entrapped, of the individual recesses to a cross-sectional area, throughout their entire depth, which will entrap liquids by capillary action, i.e. from about 5/32 to about 7/32 inch. Simply providing a larger cross-sectional area at the top of the recess would not achieve the desired positive liquid entrapment, but would result in juices flowing out of the recess when the tray is tilted or inverted.